The Vestingwet[3] (eng: Fortification Law) or Wet tot regeling en voltooiing van het vestingstelsel (eng: Law to regulate and complete the fortification) was signed on 18 April 1874. The law dealt with the defence of the Netherlands against enemy attacks.

During the occupation of the Netherlands the Germans made fortifications to prohibit the Allies to liberate the Netherlands and to protect their V2 rocket platforms in the Netherlands. The Germans built new defence lines like the Atlantic Wall but also reused the Dutch defence line like the Grebbe line.